In the upper reaches of the Chesapeake Bay watershed, Tim and Chris Camman walk daily through a thick wood, shaded by a canopy of tall hemlocks, white pines and hardwoods. Dappled sunlight filters through, with only the sounds of birds and Carrs Creek as it bubbles and swirls around the flat rocks and wood snags of its bed.

It has been several years since surveyors came through and measured where a 100-foot wide swath of forest could be felled on their 77-acre farm in New York northeast of Binghamton to make way for a natural gas pipeline. If the project goes forward, it would ultimately take about 10 percent of the land the Cammans have owned since 1988. Faded orange and pink survey flags poke out from thick brush, tied on stakes or tree branches.

“Every time I go for a walk, I can picture all of this gone,” Chris Camman said.

Bulldozers have already cleared a swath through Pennsylvania for the interstate Constitution Pipeline, which is planned to ship natural gas 125 miles to energy-hungry New York City and New England from Marcellus Shale deposits in northeastern Pennsylvania. But work stalled at the New York border last year, when that state’s Department of Environmental Conservation denied a necessary permit for the project.

“Since DEC denied the water quality permit, we’ve been able to relax a little bit,” she added. “But, excuse the language, we’re not out of the woods yet.”

The pipeline’s developer, a consortium of energy companies led by The Williams Co. Inc., has filed a lawsuit challenging the denial. The case, now pending before the U.S. Circuit Court of Appeals for the Second Circuit, is being closely watched as a bellwether that might influence other pipeline disputes.

Amid a nationwide boom in natural gas production, pipelines to transport the fuel to lucrative markets are being proposed and built all across the six-state Chesapeake Bay watershed. The projects are running into fierce, though mostly futile, resistance from environmentalists, farmers and other landowners.

A recent decision in Virginia to share review of the 600-mile Atlantic Coast Pipeline with the U.S. Army Corps of Engineers has prompted a lawsuit, after the state Department of Environmental Quality previously said it would scrutinize each of the project’s nearly 2,000 stream crossings. In Pennsylvania, the Atlantic Sunrise pipeline has been issued a conditional water quality permit. That project only needs permits for land clearing and stream crossing to go forward, with opponents threatening civil disobedience in a showdown.

In the interest of ensuring reliable energy supplies, federal law and regulations favor pipeline projects, to the point that developers can invoke eminent domain to condemn private property if owners are unwilling to sell rights of way.

But states have some say, if they’re willing to use it, because under the federal Clean Water Act, they’re empowered to review what impacts even interstate projects may have on water quality within their borders. They can “certify” the projects meet state requirements, approve them with conditions — or, as New York did in this case, deny approval.

The Clean Water Act has been used successfully by states to stop or slow down projects in the past, said Ross H. Pifer, professor and director of the Penn State Law School’s Center for Agricultural and Shale Law.

The most recent case also involved New York, where the Islander East pipeline was proposed to run 22 miles under Long Island Sound from Connecticut, supplying gas to New York City and its suburbs. Connecticut denied approval, saying that the project would destroy shellfish habitat supporting an important seafood industry in the Sound. The case concluded in 2009, Pifer recalled, when the Supreme Court refused to hear the developers’ appeal of a lower court decision upholding the denial.

In the Constitution case, New York regulators balked at approving the developer’s plans to run the pipeline through 500 acres of forest and 90 acres of wetlands and across 251 streams, with nearly a third of them harboring wild trout that are sensitive to disruption. All told, the project Williams had proposed would clear roughly 1,800 acres of land, according to documents filed with the Federal Energy Regulatory Commission. The federal commission granted its approval for the project in February.

The state’s environmental agency stated in its denial that Williams failed to adequately consider an alternative route along Interstate 88 that would have involved less environmental disruption.

The New York agency also found the impacts on streams in the company’s proposal unacceptable under state law, which requires projects to evaluate the feasibility of reducing damage when crossing streams. Under Williams’ plan, all but 21 of the 251 streams to be crossed would be dammed and diverted while the pipe is laid across the bottom. Regulators said that risked causing severe bank erosion. Such impacts can be avoided by tunneling underneath stream beds to lay pipe, but it’s much more expensive.

Williams, an Oklahoma-based company that builds and operates gas pipelines, alleges in its lawsuit that the state’s denial was arbitrary and political.

“New York is fourth in the nation for natural gas use,” said Williams spokesman Christopher Stockton. “There has been tremendous support for this project. New York’s Southern Tier needs this opportunity.”

The pipeline would move 650 dekatherms of Marcellus gas, enough to power 3 million homes, Stockton said. Taps along the pipeline are being installed for local communities to use and for two of the largest employers in the area to access the gas.

Political sentiment has been running hot in New York over hydraulic fracturing, the controversial drilling method used to extract Marcellus gas in Pennsylvania and nationwide. It involves pumping large quantities of water, sand and chemicals to free up gas trapped deep underground. Opponents of “fracking,” as it’s often called, contend that it’s responsible for a variety of environmental and health ills, including contaminated drinking-water wells. In 2015, New York banned it within its borders, the first state with proven gas reserves to do so. Earlier this year, Maryland joined in banning the drilling method.

Pipelines have become the new fracking battleground. With help from national environmental organizations, grass-roots groups are fighting the projects over their alleged impacts on the local environment as well as on climate change. Farmers and otherwise conservative landowners also have joined the opposition because of the taking of their land.

New York’s DEC came under pressure to block the Constitution project from groups such as Stop the Pipeline and Otsego 2000, both based near Oneonta, NY.

Stop the Pipeline campaigned for more than a year, writing letters, staging protests in Albany and specifically asking the DEP to deny the water quality permit, said Ann Marie Garti, an environmental attorney and a founder of the group.

“The DEC has denied [water quality permits] in the past,” Garti said. “In comments to FERC, we didn’t let them forget that.”

Since its refusal to approve the Constitution pipeline, New York has shot down a second project in the western portion of the state, again stating concerns with its effect on stream ecology plus potential impacts on sources of drinking water.

“I suspect that this isn’t going to be the last gas pipeline case unfolding,” said Penn State’s Pifer.